This invention is concerned with absorbent articles such as sanitary napkins, pantiliners, and incontinence pads that are designed to absorb and retain liquid and other discharges from the human body and to prevent body and clothing soiling. The present invention is particularly concerned with sanitary napkins that have reduced roll-over at their end regions, particularly their end edges.
Disposable absorbent articles are designed to contain body exudates and to keep such body exudates from soiling adjacent clothing and undergarments. Thus, numerous improvements have been directed towards providing better containment of such body exudates within the sanitary napkin and reducing the occurrence of soiling of garments worn over the sanitary napkin. Soiling of garments resulting from the roll-over of the end edges of sanitary napkins is particularly a problem with catamenials. Soiling at the end edges is caused by a lack of stability in the end regions and/or end edges of a pad. It is therefore desirable to provide a sanitary napkin having a limited range of motion at its ends to prevent soiling caused by roll-over. Additionally, this restricted range of motion will enhance the body-conforming capability of the pad overall.
Additionally, the roll-over of the end of the pad increases the level of discomfort or noticeability of the product by a wearer. Roll-over reduces the effectiveness of the catamenial pad by reducing the effective length of the pad, which may thereby increase the amount of fluid which may directly flow from a wearer to their undergarment.
There have been a number of recent efforts to provide catamenial pads with improved body-conforming characteristics in order to improve the leakage performance of these products. In particular, sanitary napkins have been developed which are relatively thin and flexible to better conform the sanitary napkin to the wearer. Commercially successful sanitary napkins of this type are described in U.S. Pat. No. 4,950,264, issued to Osborn, on Aug. 21, 1990 and U.S. Pat. No. 5,009,653 issued to Osborn, on Apr. 23, 1991. While these ultrathin and flexible absorbent articles work quite well, there remains a need to improve the end soiling performance of these products and to further improve their fit characteristics.
U.S. application Ser. No. 08/665,959 entitled "Generally Thin, Flexible Sanitary Napkin With Stiffened Center", filed on Jun. 18, 1996 by Osborn describes a sanitary napkin that has a stiffened central absorbent core region. Additionally, the napkin comprises flexural-resistance means in its longitudinal side regions. This application also states that this sanitary napkin has a flexure-resistance as measured through the first and second end regions which is less than the flexure-resistance as measured through the central region.
U.S. Pat. No. 5,578,025 issued on Nov. 26, 1996 to May describes a sanitary napkin having stabilizing members joined along it's sides to reduce soiling and improve fit. In one embodiment herein May describes a napkin having stabilizing members extending about the entire periphery of the sanitary napkin, i.e., including end edges. However, May does not disclose or otherwise suggest having stabilizing members or any sort of stiffened and/or absorbent members positioned only at the end regions and/or end edges of the sanitary napkin as in Applicant's embodiment. May's invention is concerned then with providing an entirely stiffened periphery and not just providing stiffness at the end edges.
While the sanitary napkins disclosed in the Osborn patents and application and the May application work quite well, the search for improved sanitary napkins, i.e., sanitary napkins specifically designed to reduce roll-over at their ends, has continued.
As products have become progressively more flexible it has been observed that there is a tendency for the products to roll-over at their end regions and specifically their end edges. This phenomena of end roll-over contributes to both soiling and wearing discomfort.
Thus, it is an object of the present invention to provide the sanitary napkin herein with stabilizing members at its end regions and/or end edges to reduce the tendency of roll over of the product at its ends.
It is also an object of the present invention to provide unitary disposable sanitary napkins herein with improved end region/edge soiling containment performance.
It is an additional object of the present invention to improve the fit of such sanitary napkins during use such that their surface conforms better to the corresponding shape of the human body.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.